[c-nsp] EUI-64 on POS interfaces

[Phil Bedard]

http://www.cisco.com/en/US/products/sw/iosswrel/ps5187/ 
products_configuration_guide_chapter09186a00806f3a6a.html

Specifically:

Interface IDs are constructed in the modified EUI-64 format in one of  
the following ways:

•For all IEEE 802 interface types (for example, Ethernet, and FDDI  
interfaces), the first three octets (24 bits) are taken from the  
Organizationally Unique Identifier (OUI) of the 48-bit link-layer  
address (MAC address) of the interface, the fourth and fifth octets  
(16 bits) are a fixed hexadecimal value of FFFE, and the last three  
octets (24 bits) are taken from the last three octets of the MAC  
address. The construction of the interface ID is completed by setting  
the Universal/Local (U/L) bit—the seventh bit of the first octet—to a  
value of 0 or 1. A value of 0 indicates a locally administered  
identifier; a value of 1 indicates a globally unique IPv6 interface  
identifier.

•For all other interface types (for example, serial, loopback, ATM,  
Frame Relay, and tunnel interface types—except tunnel interfaces used  
with IPv6 overlay tunnels), the interface ID is constructed in the  
same way as the interface ID for IEEE 802 interface types; however,  
the first MAC address from the pool of MAC addresses in the router is  
used to construct the identifier (because the interface does not have  
a MAC address).

•For tunnel interface types that are used with IPv6 overlay tunnels,  
the interface ID is the IPv4 address assigned to the tunnel interface  
with all zeros in the high-order 32 bits of the identifier.

Note For interfaces using PPP, given that the interfaces at both ends  
of the connection might have the same MAC address, the interface  
identifiers used at both ends of the connection are negotiated  
(picked randomly and, if necessary, reconstructed) until both  
identifiers are unique. The first MAC address in the router is used  
to construct the identifier for interfaces using PPP.

If no IEEE 802 interface types are in the router, link-local IPv6  
addresses are generated on the interfaces in the router in the  
following sequence:

1. The router is queried for MAC addresses (from the pool of MAC  
addresses in the router).

2. If no MAC addresses are available in the router, the serial number  
of the router is used to form the link-local addresses.

3. If the serial number of the router cannot be used to form the link- 
local addresses, the router uses a Message Digest 5 (MD5) hash to  
determine the MAC address of the router from the hostname of the router.

---------------------------------------------------

If you were to set something for the eui-64 portion, would it still  
be eui-64?  It would be a static address assignment...


Phil


On Apr 27, 2007, at 1:14 PM, Aaron Daubman wrote:

> Greetings,
>
> I was wondering if anybody could point me toward how IPv6 link-local
> addresses are generated on Packet over SONET interfaces (e.g. on a GSR
> ISE CHOC48 LC)?
>
> Also, in particular, I'm wondering if there is a way to specify an
> EUI-64 ID on POS interfaces encapsulated with either PPP or cHDLC?
>
> Thanks,
>       ~Aaron
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/